#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100000;
int n;
// [区间右端点] <左端点, 数量>
map<int, int> e[MAXN + 5];
// [1,i] 最大的合法区间权值和
int f[MAXN + 5];
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        int a, b;
        cin >> a >> b;
        a = a + 1;
        b = n - b;
        if (a > b)
            continue;
        // 区间 [a,b]
        e[b][a]++;
    }
    for (int i = 1; i <= n; i++)
    {
        f[i] = f[i - 1];
        for (auto now : e[i])
        {
            // [l,r]: w 个人
            int l = now.first;
            int r = i;
            int w = min(r - l + 1, now.second);
            f[i] = max(f[i], f[l - 1] + w);
        }
    }
    cout << n - f[n];
    return 0;
}